The present invention relates to a railroad tie having a compact design for a fixed track with an overlay of asphalt of the Getrac construction with a dowel stone which is inserted in a recess on the underside of the railroad tie and which protrudes downward into engagement with a cavity pocket of the asphalt track.
In the case of railroad ties having a compact design for fixed tracks of the Getrac construction, a very high surface pressure results when normal railroad ties are used. As a consequence, over time, the railroad tie is pressed more and more into the asphalt, so that the height adjustment of the cast track is lost. In the case of the Getrac system, the cavity pocket of the asphalt track is filled after the railroad ties or a premanufactured track grid are aligned, in order to anchor the dowel stone, since, after all, the cavity pocket must be constructed larger initially in order to be able to compensate for manufacturing and laying tolerances. This, however, presupposes, in turn, that the cavity pocket protrudes somewhat laterally beyond the railroad tie, as clean casting can otherwise not take place.
It is therefore an object of the invention to configure a railroad tie having a compact design for a fixed track with an overlay of asphalt of the Getrac construction in which less surface pressure is present and nevertheless, it is possible to fill the cavity pockets of the asphalt track after the railroad ties are aligned.
Pursuant to the invention, this objective is achieved by a railroad tie having a compact design and which is formed as a double railroad tie between which railroad tie and an adjacent railroad tie, there is only a small gap which enables a curve to be laid and which, in the region of the dowel stone on the underside, is provided with lateral constrictions for subsequently filling the cavity pockets.
Instead of the normal, wide railroad ties having a compact design previously used, double railroad ties are employed pursuant to the invention, the width of which is such that they, in each case, form only a narrow gap with the neighboring railroad tie. In this manner, the surface pressure evidently becomes very much less and the danger of sinkage into the asphalt does not arise. Due to the lateral constrictions in the region of the dowel stone, which are unusual in the case of double sleepers laid on track ballast, the cavity pockets of the asphalt track, which are in the region of these constrictions, are exposed at least at the outer edge so that, in spite of the almost complete coverage of the asphalt track by the double railroad ties, the cavity pockets of the asphalt track can still be filled subsequently and as a result, the dowel stones engaging therein can be anchored.
Moreover, the novel use of the special double railroad ties also has the advantage that, due to the great weight of the railroad ties, the load on the dowel stone in the transverse and longitudinal directions is less since the weight of the railroad ties alone largely absorbs the direct transfer of forces as a carriage passes over the railroad ties.
Moreover, it is also within the scope of the invention to provide the novel double railroad tie in the region of the pocket accommodating the dowel stone with a cavity having a low height which extends over the entire width and also over a greater length than does the recess for the dowel stone. This cavity prevents the railroad tie being supported precisely in the middle and, as a result, also the danger of breakage. Moreover, due to this gap, air can escape through this gap while the cavity pocket of the asphalt track is being filled so that this filling can take place more quickly and more uniformly.
Further advantages, distinguishing features and details of the intervention arise out of the following description of an example and the accompanying drawings.